Paravanes, Steadying Sail or Both

Has anyone got any design drawings or information on paravane rigs ? or experience and advice on using and when to deploy ??

Bebe's book, Voyaging Under Power talks about them. The struts need to be supported at or near a bulkhead at about midships. There is a supplier of the fish in the PNW somewhere who might be able to help with sizing. But you will need a naval architect to determine location and mounting strength for the struts.

I understand that they are difficult to deploy. Just like hoisting a storm sail on a sailboat, by the time you realize that you need them, they are a bitch to rig in a seaway.

Steadying sails can help, but it needs a decent sized mast with all of the support problems of the paravanes. A radar mast isn't going to cut it. And it only works on some points of sail.

David

djmarchand said:

Bebe's book, Voyaging Under Power talks about them. The struts need to be supported at or near a bulkhead at about midships. There is a supplier of the fish in the PNW somewhere who might be able to help with sizing. But you will need a naval architect to determine location and mounting strength for the struts. I understand that they are difficult to deploy. Just like hoisting a storm sail on a sailboat, by the time you realize that you need them, they are a bitch to rig in a seaway. Steadying sails can help, but it needs a decent sized mast with all of the support problems of the paravanes. A radar mast isn't going to cut it. And it only works on some points of sail. David

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Thanks for the info, more homework

This Nordic Tug is equipped for paravanes.

We have paravanes on Hobo. For open ocean travel and full displacement, having stabilization, adds significantly to the comfort level. Deployment is easy since we leave the poles out all the time once we leave the dock and only have to drop the fish in the water as needed. Retrival can get tricky sometimes. The fish run at 15 feet in flat water so if you are entering an anchorage in crap sea conditions or in an area of shoals, water depth is something you have to think about.

The engineering isn't that difficult but critical so worth getting an NAs help. I know of 2 boats within the last year, with building and installation, costs were between 10-15K based on finish on a 39-43' full displacement vessel in the US.

Maybe we'll hear from Dauntless who is having some built for him currently in Miami.

Check the archives. There are pictures and several discussions.

I have paravanes - flopper stoppers. I just finished rigging them and trying them out. They are easy to deploy, just drop the fish overboard, but a prick to stow. The fish and chain is heavy and dragging them over the railing and putting the fish back in their holders is just too much for me. I was thinking of moving the fish to the stern, then using some tackle to swing them backwards to a rear-mounted store.

Then again I thought I might just take them off again and trash 'em.

Forgot the photo:

Weil first up I will say its horses for courses. I would be happy with a fully fledged motorsailer, but a lot of steadying sails, such as those on Grand Banks are pretty useless at moderating roll.

I'd suggest you look at good active fin stabilizers, such as Naiad. You can probably get them in for around $60k all up. You can likely get paravanes or steadying sails installed more cheaply, but there a bunch of stuff to store and manage with them and non-trivial physical requirements also.

With fins there is no operating hassle at all - just push the button to turn them on. They were probably rare in Beebe's day, and have come a long way in recent years with accelerometers in the control boxes to adjust the fins very early in the roll period. And great reliability. The latest Edition of Beebe's book really suffers because they don't have any first hand knowledge of how good active fins (good brand ones at least) have become. You get a very flat ride, and with good design they will be quite effective from 5 kn or so. Much better efficiency than paravanes or steadying sails.

Gyro stabilization starts to be possible at those numbers. And works at anchor. My preference is flopper stoppers, but I like stuff I can fix myself. Simple rules. And I can run a couple of trolling lines off each boom. The "fish" seem to be magnets for tuna and wahoo. When you troll a weedline you sometimes get a whole school of Dolfin(mahi mahi) on each paravane. Just toss a jig attem and your hooked up. Fun, if you like to fish, which we do.

I had the choice of gyro for the same cost as the Naiads. But the gyro needs min 2.5kW to run, I didn't want to run a genny at anchor. Plus, the gyro takes quite a bit of internal room. I t would have fitted nicely where the genny was, but then where could I put the genny?

A friend with a no-name gyro drew my attention to another issue. The gyro caused a quick roll correction, almost a snap back - it was so sever it made his wife seasick. Now, the better brand might not do it, I don't really know. But this is where the active fins shine - they start to correct immediately the roll starts due to the accelerometer input, then reduce angle of attack to smooth everything out. They do need to be installed and tuned properly but then are simply unbelievably good.

markpierce said:

This Nordic Tug is equipped for paravanes.

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Huh! Don't think I have seen a tug-style with a paravane rig!

I have used both paravanes and active stabilizers and if there was a $15k premium I would do the vanes. As much as I like to have a tech boat I like the rugged simplicity of vanes. Are they a pain in the ass... at times they are.. selecting a different setting or activating/deactivating active systems is certainly nice though. Having the fins in the water all the time and the cost are the negatives.

Here in the PNW there are a lot of boats (Nordic tugs included) with vanes and they do work well.

Below is a pic on Volunteer with the fish doing their job with wind and waves on the stern

HOLLYWOOD

To be of much use the steading sails will need to be the same size as for a motor sailor .

And then they still will not work on many headings.

The FS and their use is really up to the skill of the operator ,there are many systems to get them out of the water.

Sometimes the easiest is to simply STOP , and it becomes very easy.

Vane technology

Vanes don't have to made out of heavy material to work well. When I was thinking about stabilizers I talked with a few west coast fishermen working out of the bay area. Most of them made their own from plywood or Starboard. Some were weighted with lead other had carefully designed in running angle. All of them had worked a little fin that kept them from hunting. I have a friend who had a guy failure and holed his boat. His were made from steel plate. He and his brother bailed with 5 gallon buckets for 24 hours before making Moss Landing.
I have Niad 6ft stabilizers on my boat. They have been absolutely trouble free. They do slow the boat about a 1/2 knot when compared to the same hull without stabilizers. A friend of mine with a Kady Krogen 39 has Niad Stabilizers. When he turns them off his wife comes up and slaps him. Another friend with a Nordhavn 40 has all three, stay sail, paravanes and Niads. Installed in that order.
Captainoftrasea have really hard chines and a fairly flat hull, I would guess that you are going to have a lot of primary stability and really only need stability in really large sea conditions. Low ballast may be more effective.
This is where a good navel architect comes into play.

Scary said:

Vanes don't have to made out of heavy material to work well. When I was thinking about stabilizers I talked with a few west coast fishermen working out of the bay area. Most of them made their own from plywood or Starboard. Some were weighted with lead other had carefully designed in running angle. All of them had worked a little fin that kept them from hunting. I have a friend who had a guy failure and holed his boat. His were made from steel plate. He and his brother bailed with 5 gallon buckets for 24 hours before making Moss Landing.
I have Niad 6ft stabilizers on my boat. They have been absolutely trouble free. They do slow the boat about a 1/2 knot when compared to the same hull without stabilizers. A friend of mine with a Kady Krogen 39 has Niad Stabilizers. When he turns them off his wife comes up and slaps him. Another friend with a Nordhavn 40 has all three, stay sail, paravanes and Niads. Installed in that order.
Captainoftrasea have really hard chines and a fairly flat hull, I would guess that you are going to have a lot of primary stability and really only need stability in really large sea conditions. Low ballast may be more effective.
This is where a good navel architect comes into play.

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Have additional two tons of ballast to add between forward frames 4 and 5 need to see how she lies really, but also have a hollow skeg under the engine room. This would easily hold additional 3 tons , in the design this is where additional ballast is installed if you add a flybridge.

Scary said:

...
I have Niad 6ft stabilizers on my boat. They have been absolutely trouble free. They do slow the boat about a 1/2 knot when compared to the same hull without stabilizers. ...

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Sails have the advantage of adding to boat speed rather than subtracting. Some Diesel Ducks are equipped with both paravanes and sizable sails.

On the day this photo was taken, the Coot's main (smaller) sail added 0.2 knots with mild to moderate wind on the beam. If the larger jib was hoisted also, the sails would have added a half knot. The sails can reduce boat roll by a fraction.

My rounded hull rolls terribly in a beam sea when the swell gets in synch with the natural roll of the boat.

By raising the sails (300 square feet main and 100 square foot jib), the roll stops almost completely, and I gain a couple of knots. Raising or lowering the sails takes about 2 minutes even when singlehanded.

It works great under all conditions except when there is less than 5 knots of wind. In conditions when the wind is on the nose and the swell is at 45 degrees, I have to alter course about 20-30 degrees to make use of the sails and steady things out. I then get the roll reduction, although only a little extra speed.

The sails stop the roll, but not the "hobby horsing" when running directly into the big swell. They do however, seem to help the boat to punch through the swell in a more consistent fashion.

In summary, without the sails the local sea conditions would make boating uncomfortable for me about 40% of the time. The sails reduce this to 10%. Good value.

Captain-we have ABT active fins, 9 sqft, on a 58' 50+ton boat. Virtually trouble free (so far!) and tremendously effective. That said, your hard chine and flat hull shape may make installation of active fins a bit problematical. Installation is most often around the turn of the bilge so they are roughly 30-45 degrees from horizontal. That does not look to be possible on your hull. A gyro may be your only option for active stabilization, but as noted that requires constant power. Also noted before, that shape itself will ameliorate a lot of roll issues except in very heavy seas.

captainoftrasea said:

Thanks for the info, more homework

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And in that vein, more reading assignments :

http://publications.iot.nrc.ca/documents/IR/IR-2007-10.pdf

Transportation Safety Board of Canada - Marine Investigation Report M98N0064

Transportation Safety Board of Canada - Marine Investigation Report M90N5017

Transportation Safety Board of Canada - Marine Investigation Report M12W0062

The TSB reports aren't meant to be "OMG THESE THINGS ARE DANGEROUS!!" rather a reminder that, like a lot of things on boats, they need to be designed and installed properly and checked regularly.

Also, if you're out in conditions where you really need them it might be a good idea to keep your hatches closed and dogged.

markpierce said:

On the day this photo was taken, the Coot's main (smaller) sail added 0.2 knots with mild to moderate wind on the beam. If the larger jib was hoisted also, the sails would have added a half knot. The sails can reduce boat roll by a fraction.

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Mark, how long is the Coot and how tall is your mast? Is it a deck stepped mast? Is there a compression post to the keel? What type of ballast?

I'm thinking of adding a mast my boat:


I just need to find some more detailed drawings. Apparently they made 4 or 5 of these.

dhmeissner said:

Mark, how long is the Coot and how tall is your mast? Is it a deck stepped mast? Is there a compression post to the keel? What type of ballast?

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The Coot's hull is 35'8" long.

Don't know how tall the mast is. Compare height of pilothouse door to mast.

The mast rests on the pilothouse roof. It is near the back bulkhead of the pilothouse. Except for the PH roof, the superstructure is steel.

There is no ballast. The hull is for a slow-speed motor boat. Boat weight is 14 tons. There is a small keel to protect propeller and rudder (less than 4-foot draft). It's not a motorsailer. It's a sail-assisted motor vessel.

Now for my 2 cents worth.
I have just completed installing a ketch rig on my hard chine timber displacement cruiser at the same time I upgraded my flopper stoppers to full functioning paravanes.
NOTE.. I am still in the process of refining the systems and will be back on the boat for a few weeks as of next Monday.
So far, the rig works a treat and is very simple is as much as all sails are on furlers and halyards are controlled from the fwd brow of the wheelhouse.
The parvanes are great but I still have a few modifications to make. This trip I am fitting some heavy springs and trying out another pair of fish that I have.
I think I will eventually stow the fish on either side of the swim platform when not in use for long periods and at other times will stow them in small brackets on the arms.
I run dynex stays and the fish run on chains at present but I also have a pair of 10 mm dynex lines to run the fish off.

One of the attached photos is of a similar boat to my own ( the one on the hard outside the shed) she has a ketch rig, TRACT stabilisers and flopper stoppers, all bases covered.

As I progress I will add some more information

sorry, the mail is shipsdoctor@pocketmail.com

What is that strange structure on the mast that cuts through the funnel?

Gorgeous boat but the canvas just wrecks it.

That structure is the mizzen mast lower spreader, this keeps the stays vertical down the vessels side and I didn't want to get rid of the funnel so we adapted it.
The sails are good in winds 12 knots and above and save a lot of fuel on long passages up the Queensland coast and beyond.

A lot of traditional vessels have been built this way as motor sailors here in Queensland

Cheers
Benn

dhmeissner said:

Mark, how long is the Coot and how tall is your mast? Is it a deck stepped mast? Is there a compression post to the keel? What type of ballast?

I'm thinking of adding a mast my boat:

I just need to find some more detailed drawings. Apparently they made 4 or 5 of these.

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Do you have the exact same boat that just doesn't have the mast?

If so..maybe the reinforcement might already be there...just no mast/rigging.

If you get to a large enough sail area...the I'm sure a compression post or similar construction would be necessary...just a question of how much and where you want to put it.

If I ever wanted to set something like that up...no matter what it took, I would want a tabernacle to lower it easily. It's so nice to keep going and not worry about timing bridges. I can lower my mast to make a half dozen of so bridges on the ICW and the flexibility in moving schedule is greatly appreciated. My boat doesn't have a tabernacle but I can still get my mast down in about 10 minutes with the aid of my power winch I added last year.

We have a similar setup that Larry has on Hobo. The Poles and paravanes work very well and I don't find them difficult to deploy, and while we don't use them that often, we are glad to have them and expect to use them more frequently on our trips this summer. Active stabilizers would be a much more costly install with more costly maintenance. Plus the active units are always in the water contributing drag even in calm seas. Here is a a photo of the p and p's in use... Jim, Sent from my iPad using Trawler

A steading sail does not a motor sailor make.

I posted here the formula the insurance co used to decide if it was a true motor sailor.

Cant find it now.

There requirement was for just enough sail area to beet off the proverbial lee shore.

Sea Eagle has both ABT active stabilizers and Paravanes. We use the active stabilizers far more often than the paravanes (push of a button vs finding someplace calm to deploy/recover the fish).

Because the boat doesn't have a mast (fiberglass stack instead), the stack had to be reinforced and the fish are smaller than is usual to keep the strain on the stack down. Still, even with the small fish, it is no fun recovering them in lumpy weather or dealing with dangling crab pots.